Infinity SW stacking issues, 4.2.2.1 core, mono Infinity

[scpanish]

Hi All,

Does anyone have experience with resolving odd failures to stack and 0 FWHM values?  I am generally using SW  with Auto Calc Movement enabled, Add Q disabled, Auto Stack Reset disabled.  There are various issues.  Sometimes FWHM values look normal for this setup (7 to 12) and stacking will proceed for a few frames, then a few "not stacked with good FWHM values", then a few more frames will again stack. If the "not stacked" is caused by image movement, why would stacking resume?  Another scenario is the FWHM value shows as 0, and stacking will still proceed normally (see attached image, stack of 45 sec exposures).  Other times there will be a 0 FWHM value and no stacking will occur.   The general problem is that the SW just doesn't seem to want to stack for no clear reason that is apparent to me.  Unfortunately the SW doesn't seem to have any logs.

Does anyone else see this sort of thing?  Does newer software help?  Just FYI the setup is a C11 on an AP1200 mount, polar alignment isn't perfect but isn't horrible either.  A .fit is available for that image if that is of any use to anyone.

thanks,

Steve

[scpanish]

Hi Sirius19,

The .jpg posted IS the image from a stack of entirely 0 FWHM subframes.  In this case no subframes were "rejected" (after all, 0 is less than the FWHM reject level I had set) and no subframes were eliminated as "not stacked".  So it was one of the lucky captures that worked, in that it created a stacked image.  Although it would likely have been better if the poorer subframes were rejected.  Most of the failures I'm seeing result in either no stack, or a very small stack, and sometimes it also looks like a failure to plate solve (align the images properly).

Did you perhaps mean that you wanted to look at the .fit?  That is too big to post but if you want that give me your email addr and I'll send it to you.

Steve

[scpanish]

Thanks, I appreciate the help!

The exposures are generally long ( 30 to 45 sec ) and the camera has USB 2.0, computer is a very fast gaming laptop with lots of memory.  So I don't think any delay between the camera and the computer can be significant.  As soon as the exposure progress histogram indicates the subframe is finished, I see the FWHM updated.  It does not change until the next subframe.

As you suggested, I'll turn off stacking and catch a 0 frame, that should be interesting.  It happens about 75% of the time so should not be difficult.  I'll try that at the first opportunity, which may be a few days off. 

I'll also look at a replay.

Have you tried the Infinity SW that comes in the new 5 core software? 

Atik, if you are listening....logs!!!  What kind of software lacks logging???

Steve

[scpanish]

I had a short period tonight before clouds moved in.  No FWHM or stacking issue for the one test image I had time for, FWHM numbers were all reasonable.  This was shooting through thin clouds.  I'll try again tomorrow if it is clear.

Steve

[scpanish]

Hmmm....

Dividing any number by 0 gives an undefined result, not 0!  But adding in Q may be worth trying.  But I have new information.

I have no trouble getting the 0 FWHM, generally on fairly sparse star fields.  It seems less likely to happen viewing something like a bright nebula or galaxy.  There is a lot of background light now due to the moon and somewhat high moisture in the air.  But also the image quality was poor, as though the stacking alignment was poor.   I don't know how to examine the FIT files (need to learn that) which might give info.

So it seemed appropriate to try ArtemisCapture to separate out the issues.  What I see is that the individual captured frames look sharper than the stacked frames from the Infinity application.  Trying a dark frame was revealing - lots and lots of hot pixels, and temp was 18 deg F.  When I see example pictures of hot pixels in books or articles, there are a few sprinkled around the frame.  This camera has a significant percentage throughout the frame.   The bias frames are noisy too, but I don't know what they are supposed to look like.   I'm no expert, but it seems likely that the sensor or associated electronics in this camera are failing.  The Infinity software does some kind of hot pixel removal, but in this case maybe it is inadequate and the image is swamped with noise - which results in the lousy looking images.  The flats were also distressingly non-uniform with the bottom of the frame much darker than the top.  I'll try the standard post-processing techniques - time to learn them anyway - and see if it helps.

I'm going to be away for most of April so it seems like a good opportunity to send the camera in for a checkup.  The power connector is a disaster anyway and needs replacement. 

STeve